mcpha.py: better factorization

mcpha.py

 #!/usr/bin/env python3
-"""mcpha: Multi-Channel Pulse Height Analyser  
+"""mcpha: Multi-Channel Pulse Height Analyser 
 
+    Client script for displaying the output of the MCPHA application 
+    running on a RedPitaya FPGA board
+
+    Modified version of mcphy.py by Pavel Demin  
 
-      Client script for displaying the output of the MCPHA application 
-      running on a RedPitaya FPGA board
 """
 
+# differences w.r.t. original version marked with " # !gq"
+
 import argparse # !gq
 
 import os
@@ -57,7 +61,10 @@ class MCPHA(QMainWindow, Ui_MCPHA):
 
     # !gq get command line arguments
         self.parse_args()
-        
+        self.get_physical_units()
+
+       
+    # !gq end    
         # initialize variables
         self.idle = True
         self.waiting = [False for i in range(3)]
@@ -87,7 +94,6 @@ class MCPHA(QMainWindow, Ui_MCPHA):
         self.rateValue.lineEdit().setAlignment(Qt.AlignRight)
         for i in range(self.rateValue.count()):
             self.rateValue.setItemData(i, Qt.AlignRight, Qt.TextAlignmentRole)
-        # !gq self.rateValue.setCurrentIndex(0)            
         self.rateValue.setCurrentIndex(1)
         self.rateValue.currentIndexChanged.connect(self.set_rate)
         # address validator
@@ -110,7 +116,7 @@ class MCPHA(QMainWindow, Ui_MCPHA):
         self.readTimer = QTimer(self)
         self.readTimer.timeout.connect(self.read_timeout)
 
-        # !gq set defaults 
+        # !gq set defaults and units
         self.osc.levelValue.setValue(self.trigger_level)
         # !gq end
         
@@ -126,6 +132,14 @@ class MCPHA(QMainWindow, Ui_MCPHA):
         self.ip_address = args.ip_address
     # !gq end
 
+    def get_physical_units(self):
+        """get physical units corresponding to ADC units and channel numbers
+        """
+        # Voltages: 4096 channels/Volt
+        self.adc_unit = 1000/4096
+        # time per sample at sampling rate of 125 MHz / decimation_factor
+        self.time_bin = 0.008
+        
     def start(self):
         self.socket.connectToHost(self.addrValue.text(), 1001)
         self.startTimer.start(5000)
@@ -433,12 +447,12 @@ class HstDisplay(QWidget, Ui_HstDisplay):
     def adc2mV(self, c):
         """convert adc-count to Voltage in mV
         """
-        return c * 1000/4096 * self.factor
+        return c * self.mcpha.adc_unit * self.factor
 
     def mV2adc(self, v):
         """convert voltage in mV to adc-count 
         """
-        return v *4096/(1000 *self.factor)
+        return v / (self.mcpha.adc_unit * self.factor)
     # !gq end helper
         
     def start(self):
@@ -687,8 +701,8 @@ class OscDisplay(QWidget, Ui_OscDisplay):
         self.ax = self.figure.add_subplot(111)
         self.ax.grid()
         self.ax.set_ylim(-4500, 4500)
-        self.ax.set_xlabel("time bin")
-        self.ax.set_ylabel("ADC counts")
+        self.ax.set_xlabel("sample number")
+        self.ax.set_ylabel("ADC units")
         # gq
         self.ax_x2=self.ax.secondary_xaxis('top', functions=(self.tbin2t, self.t2tbin))
         self.ax_x2.set_xlabel("time [µs]", color='grey', size='x-large')
@@ -739,26 +753,26 @@ class OscDisplay(QWidget, Ui_OscDisplay):
     def tbin2t(self, tbin):
         """convert time bin to time in µs
         """
-        idf = self.mcpha.rateValue.currentIndex()
-        df = 1 if idf == -1 else MCPHA.rates[idf]
-        return (tbin-self.pre)*df*0.008 
-
+        dfi = self.mcpha.rateValue.currentIndex()  # current decimation factor index
+        df = 4 if dfi == -1 else MCPHA.rates[dfi]  # decimation factor
+        return (tbin-self.pre)*self.mcpha.time_bin * df
+ 
     def t2tbin(self, t):
         """convert time in µs to time bin 
         """
-        idf = self.mcpha.rateValue.currentIndex()
-        df = 1 if idf == -1 else MCPHA.rates[idf]
-        return t/(df*0.008)+self.pre
+        dfi = self.mcpha.rateValue.currentIndex()  # current decimation factor index
+        df = 4 if dfi == -1 else MCPHA.rates[dfi]  # decimation factor
+        return t/(self.mcpha.time_bin * df)+self.pre
 
     def adc2mV(self, c):
         """convert adc-count to Voltage in mV
         """
-        return c * 1000/4096
+        return c * self.mcpha.adc_unit
 
     def mV2adc(self, v):
         """convert voltage in mV to adc-count 
         """
-        return v *4096/1000
+        return v / self.mcpha.adc_unit
     # gq end
     
     def start(self):
@@ -888,14 +902,15 @@ class GenDisplay(QWidget, Ui_GenDisplay):
 
     # gq
     def adc2mV(self, c):
-        """convert adc-count to Voltage in mV
+        """convert adc-count to Voltage in mV 
+           !!! there is a factor of two betwenn channel definition here and in hstDisplay !
         """
-        return c * 500/4096
+        return c * self.mcpha.adc_unit/2
 
     def mV2adc(self, v):
         """convert voltage in mV to adc-count 
         """
-        return v *4096/500
+        return v * self.mcpha.adc_unit*2
     # gq end
         
     def start(self):